package com.jxb.netty.example.nio;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.util.Iterator;
import java.util.Set;

public class NioClientHandle implements Runnable{

    private String host;
    private int port;
    private volatile boolean started;
    private Selector selector;
    private SocketChannel socketChannel;

    public NioClientHandle(String host, int port) {
        this.host = host;
        this.port = port;
        try {
            this.selector = Selector.open();
            this.socketChannel = SocketChannel.open();
            //设置通过为非阻塞模式
            socketChannel.configureBlocking(false);
            this.started = true;
        }catch (Exception e) {
            e.printStackTrace();
        }
    }


    @Override
    public void run() {
        try {
            doConnect();
        }catch (IOException e) {
            e.printStackTrace();
        }
//        //循环遍历selector
//        while(started) {
//            try {
//                //selector中的时间每隔一秒钟进行唤醒
//                int select = selector.select(1000);
//                Set<SelectionKey> keys = selector.selectedKeys();
//                Iterator<SelectionKey> iterator = keys.iterator();
//                SelectionKey selectionKey = null;
//                while (iterator.hasNext()) {
//                    selectionKey = iterator.next();
//                    iterator.remove();
//                    try {
//                        //获取事件，进行处理
//                        handleInput(selectionKey);
//                    }catch (Exception e) {
//                        //处理异常，关闭通道
//                        if (selectionKey != null) {
//                            selectionKey.cancel();
//                            if (selectionKey.channel() != null) {
//                                selectionKey.channel().close();
//                            }
//                        }
//                    }
//                }
//            } catch (IOException e) {
//                e.printStackTrace();
//            }
//        }
    }

    private void handleInput(SelectionKey key) throws IOException {
        if (key.isValid()) {
            //获取当前的事件channel
            SocketChannel sc = (SocketChannel) key.channel();
            //连接事件
            if (key.isConnectable()) {
                if (sc.finishConnect()) {
                    socketChannel.register(selector,SelectionKey.OP_READ);
                }else {
                    System.exit(1);
                }
            }
//            if (key.isReadable()) {
//                ByteBuffer buffer = ByteBuffer.allocate(1024);
//                int read = sc.read(buffer);
//                if (read > 0) {
//                    //将缓冲区当前的limit设置为position，position=0
//                    //用于后续缓冲区的读取操作
//                    buffer.flip();
//                    //根据缓冲区可读字节创建字节数组
//                    byte[] bytes = new byte[buffer.remaining()];
//                    //将缓冲区可读字节数组复制到新建的数组当中
//                    ByteBuffer buffer1 = buffer.get(bytes);
//                    String result = new String(bytes,"UTF-8");
//                    System.out.println("客户端收到消息：" + result);
//                }else if (read < 0){
//                    key.cancel();
//                    sc.close();
//                }
//            }
        }
    }

    private void doConnect() throws IOException {
        boolean connect = socketChannel.connect(new InetSocketAddress(host, port));
        if (connect) {
            socketChannel.register(selector, SelectionKey.OP_READ);
        }else {
            socketChannel.register(selector,SelectionKey.OP_CONNECT);
        }
    }

    public void sendMsg(String msg) throws Exception{
        doWrite(socketChannel, msg);
    }

    private void doWrite(SocketChannel channel, String request) throws IOException {
        //将消息编码为字节数组
        byte[] bytes = request.getBytes();
        //根据数组容量创建ByteBuffer
        ByteBuffer writeBuffer = ByteBuffer.allocate(bytes.length);
        //将字节数组复制到缓冲区
        writeBuffer.put(bytes);
        //flip操作
        writeBuffer.flip();
        //发送缓冲区的字节数组
        /*关心事件和读写网络并不冲突*/
        channel.write(writeBuffer);
    }
}
